Is it true that lichen is a symbiotic association between a fungal and an algal partner?

 Symbiosis is the interaction between two different organisms living in a close physical association that benefits from each other.

Lichens are a symbiosis of a heterotrophic fungal partner and a photosynthetic algal component. The fungi in the lichen provide a constant supply of water and nutrients to the algae whereas algae photosynthesize food and provide it to the fungi. This symbiosis allows lichens to grow in a wide range of environments, including rocks, trees, and soil. Lichens are not plants, and they do not have roots or leaves. They are a unique type of organism that has characteristics of both fungi and algae.